Since it's cold, let's discuss the whole, "you can't run an engine w/out exhaust mani

That's just an old wives tale, Chuck Norris invented the exhaust flappers.

 

Exotic metals in race engines are prone to damage from cold air entering the exhaust port after it is shut off.

 

just had to add this one since the thread will crash and burn anyway.

 

Didn't the guy with the hat die last week? & the redhead is no longer on the show?
Just thoght I'd chime in again before this gets closed!

 

Well never mind! Nothing on Google & she's on maturnity leave.

 

OK, i think i'm going to conclude (and i also learned a bit on human behavior as well......) that running w/out manifolds/flappers/minimum lenght of exhaust pipe etc. in the cold is probably not harmful to the engine.

But, i plan on running at least a manifold whenever running an engine because it makes no sense or benefit to run an engine without a manifold in the first place----it's probably a good idea to have the exhaust gases properly evacuated away from the engine.

Someone told me that the reason why some commercial trucks have a flapper on the exhaust pipe was that "when the engine shuts down, it turns backwards for 1/4 turn and this ****s in cold air and so the flapper is to keep it from ****ing in cold air and damaging the exhaust valve."

i surmize that this notion/belief has been nullified.